98 Civic brake light

My wifes 98 Civic DX's brake light is staying on. When you first start the
car, it comes on, like you have the parking brake on, but of course, it
isn't. After amybe 10 minutes of driving it will go off. Is there a sensor
in the parking brake line that may be sticking that anyone knows of? The
brake system itself seems to be fine and the fluid level is fine.

 

Check the brake fluid in the master cylinder. There is a low fluid warning
circuit that uses the brake light. Or the parking brake could be adjusted
too loose and its not hitting the switch. There is a switch at the base of
the brake handle.

Check the fluid level first.